JP Patent Publication 2010-78156A (hereinafter JP ‘156) and JP Patent Publication 2014-202238A (hereinafter JP ‘238) disclose known automatic clutch devices for automatically engaging and disengaging manual transmissions (MT) and automated manual transmissions (AMT).
The automatic clutch device disclosed in JP ‘156 is configured such that when the clutch pedal is depressed, hydraulic pressure is generated in a master cylinder mechanically connected to the clutch pedal, and is supplied to a clutch release cylinder. The clutch release cylinder pivots a release fork, thereby pressing a release bearing, a pressure plate is pressed against a flywheel under the pressing force applied to the pressure plate from the release bearing, and the clutch device engages.
The automatic clutch device disclosed in JP ‘238 is configured, similar to the clutch device of JP ‘156, such that hydraulic pressure generated in the master cylinder by depressing the clutch pedal is supplied to a clutch release cylinder, the clutch release cylinder pivots a release fork, the release fork presses a release bearing, and the clutch device disengages.    Patent Document 1: JP Patent Publication 2010-78156A    Patent Document 2: JP Patent Publication 2014-202238A
Since the clutch device of either of JP ‘156 and JP ‘238 is configured to be engaged and disengaged by pivoting the release fork with the clutch release cylinder, such clutch devices tend to be large in size. Moreover, since such clutch devices require a hydraulic pump, and pipe connections between the hydraulic pump and the clutch release cylinder, a large installation space is needed for such clutch devices.